Coffee machine



FIG. 1 is a perspective view of a coffee machine showing my new design;

FIG. 2 is a top plan view thereof;

FIG. 3 is a front elevational view thereof;

FIG. 4 is a front side elevational view thereof, the left side elevational view being a mirror image thereof;

FIG. 5 is a rear elevational view thereof; and

FIG. 6 is a bottom plan view. 

The ornamental design for a coffee machine, as shown and described. 